Method and apparatus for compressing foam blocks for storage and/or shipment

ABSTRACT

Method and apparatus for the compression and restraint of blocks of polyurethane foam or similar material to a small percentage of their original volume to reduce shipping and storage space. The blocks are compressed initially in the direction of at least one of the axes and are restrained in the direction of one of the other axes. Then, a restraining sleeve or a plurality of restraining bands holds the block in the compressed condition in the direction of the compressed axis and also prevents rebound or expansion in all directions of compression.

United States Patent [19] [111 3,811,242 i451 May 21,1974

Hayford, Jr. et al.

3,590,73l 7/l97 l Nichols .7 l00/232X METHOD AND APPARATUS FOR COMPRESSlNG F A BLOCKS FOR 3,524,297 8/l970 Falborg et al 53/!24 D X STORAGE AND/OR SHIPMENT [76] Inventors: William H. Hayford, Jr., Summit Primary Examiner-Travis S. McGehee Point, Ringwood, NJ. 07456; Attorney, Agent, or Firm-Samuelson & Jacob Theodoreflayford, 204 Boulevard, Glen Rock, N]. 07452; Donald S. v I

P N. Y gigggrd, 26 ark Pl Paramus J ABSTRACT Filedi 1972 Method and apparatus for the compression and re- [211 App]. NO; 315,614 straint of blocks of polyurethane i'oamor similar mate'- rlal to a small percentage of their original volume to reduce shipping and storage space. The blocks are [5 53/24, 53/ Di 53/124 TS, compressed initially in the direction of at least one of 100/42, 100/232 the axes and are restrained in the direction of one of Illlt. .f the other axes; Then a restraining leeve or a plurality Fleld of Search 124 D, 124 of restraining bands holds the block in the compressed 100/42, 232 condition in the direction of the compressed axis and also prevents rebound or expansion inall directions of References Cited compression.

UNITED STATESPATENTS i 1,257,559 2/191 8 Webb, .l .I 100 42 12 Claims, 14 Drawing Figures l 1 I 32 i 257 34 26 28"; 4 I

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METHOD'AND APPARATUS FOR COMPRESSING FOAM BLOCKS FOR STORAGE AND/OR SHIPMENT The invention relates to a method and apparatus for compressing blocks or buns of polyurethane foam or similar material to facilitate their economical shipment and/or storage.

Polyurethane foam, a low density, flexible material with open air cellular structure, is used in large quantities for the protection of fragile equipment during shipment and transportation. Maximum protection of such equipment is usually obtained when the foam is in its most expanded condition, namely, when the air cells within the material are largest. However, the user of the foam blocks for equipment protection is frequently located a long distance from the manufacturer of the foam blocks. Accordingly, it is desirable to be able to ship and store quantities of blocks or buns so that they will occupy the smallest posible volume. Ideally, one desires to compress the bun a maximum amount, to store it in the compressedand restrained condition and to obtain substantially full expansion to the original voltime upon removal of the restraints.

Prior art methods have been used to produce some compressed foam block packages. Since the foam block would buckle if only one of the longer axes were compressed, compression was usually carried out in the direction of the shortest axis. As a result, it was possible to obtain only a limited amount of compression with a relatively large compressive force. Moreover, because of the nature of the material, the restraints necessary to while holding the block so compressed, compressing the block in the direction ofa second axis (usually the longest or next longest) by an amountof'the order of 10 percent to 75 percent. Now, the first compressive force is removed and the block remains compressed, in the direction of the first axis without bulging. The block is now wrapped in a sleeve or is tied with straps of wire. plastic or similar material so as to continue to restrain expansion in the direction of the second compressed axis. The block is now ready for shipment and/or storage. In the event that a particular space volume is required for the compressed bun or block. the third axis may be compressed and restrained by the sleeve applied to the second compressed axis.

It is an important object of the invention to provide a method and apparatus for producing -a compressed package of foam blocks or buns to maximize economical storage and/or-shipment of the blocks.

It is a further object of the invention to utilize the unique property of the foam material which has been discovered by applicants to provide such a method and apparatus.

Yet another object of the invention is to provide a highly efficientpackaging method wherein a high degree of compression is achieved and which is suitable to a wide variety of initial and compressed sizes.

It is a still further object of the invention to take advantage of the discovered, unique property of the material, namely, the high internal friction between the materials cell walls which is developed by sequential compression in the direction of two axes of the block.

It is yet another object of the invention to provide a method and apparatus for compressing a foam block whereby maximum compression is obtained from the use of a minimum amount of compressive force.

These and other objects, advantages, features and uses will be apparent during the course of the following description when taken in conjunction with the accompanying drawing, wherein:

FIGS. l-7 are diagrammatic views showing the steps of the invention utilizing compression in the direction of two axes of the block to achieve packaged compression thereof;

FIGS. 8 and 9 are views similar to those of FIGS. 1-7 and which, together with FIGS. l-5 show the steps of the invention utilizing compression in the direction of 7 three axes of the block to achieve packaged compression thereof; 7

FIG. 10 is a perspective view'of a preferred embodiment of apparatus of the invention,

FIG. 11 is aview similarto that of FIG. 10 showing apparatus for compressing a block in the direction of all three axes;

FIG. 12 is a top plan view of a pair of compression bars for use in the machines of FIG. 10 or FIG. 11.

FIG. l3v is a view similar to that of FIG. 12 of an alternate form of compression bars for use in the machines of FIG. 10 and FIG. 11; and

FIG. 14 is a diagrammatic view similar to that of FIG.

' 9 showing the application of straps to keep the block of material compressed. 7

When compressing an. unstable column (such as polyurethane foam), for example, in the direction of its major (longest axis), the column will buckle. However, if the column is restrained from buckling in the direction of either or both of the other axes by either limiting the outward buckling action or by applying aminor compressive force in the direction of either of these axes the major axes compression will take place uniformly. v t

When the major axis is so compressed to and beyond a critical degree at which internal collapse occurs, additional compression takes place upon the imposition ofa relatively minor increase in the compressive forces. Thus, a high degree of compression is attained effectively without requiring a proportionate increase in the compressive forces.

Once compressed beyond the point of internal collapse, the restraining or compressive forces applied to the intermediate or minor axes may be reduced or eliminated without subsequent buckling of the column.

If a substantial compression of the intermediate or minor axes, or both, is achieved prior to or concurrent with initial compression of the major axis and the major axis is substantially compressed, a unique and high internal friction developes. This characteristicpermits the decreased and complete removal of the compressive forces on the intermediate and minor axes without ered to a table 36. The table 36 may conveyor system, ifdesired.

nomics of the packaging system and restraints show that maximum compression in the. direction of the major axis is the most desirable. I

In .the foregoing discussion, the longest axis has been denominated the major axis, the shortest axis has been referred to as the minor axis and the other axis has. been called the intermediate axis. However, the teachings of the invention apply with equal force to cubes-orto shapes other than parallelopipedons.

In the drawing, wherein, for the purpose of illustration there are shown perferred embodiments of the invention, and wherein like numerals designate like parts throughout the same, the numeral designates a machine of the invention, generally. Machine 20 is shown diagrammatically in FIGS. 1-7. Machine 20 is seen to comprise a frame 22, a lower plate or table 24 and an upper plate 26. A polyurethane foam block or bun isplaced on plate 24 (FIG. 1) and in this particular illustration is a parallelop'ipedon having three axes differing in length. One axis extends in the direction of arrow 21 of FIG. 1 and another extends in the direction of arrow 23.

FIG. 2 shows the next step in the method of the invention wherein a pair of liners of plastic, paper board or similar material have been placed as shown and table 24 and plate 26 have moved to the position shown to thereby compress the block 25 in the direction of arrow 23. The liners 30 serve to reduce friction and bulging in the direction of the restrained axis when packaging later in the'process. l

FIG. 3 shows the position of block 25 after the block was first-compressed in the direction'of arrow 23 and then was compressed in the direction of arrow2lby the opposedpairs of compression bars 28. Next, the compressive .for'ce in the directionof arrow 23 is removed (FIG. 4). Because 'of the nature of the material and the property discovered by.applicants, the block does not bulge in the direction of the axis of. arrow 23 into the sleeve 32 while the compression in the direction of arrow 21 is maintained by bars 28. As the ram 34 pushes the block-25, the friction between the block 25 and the sleeve 32 causes the block to carry, the sleeve with it. If liners 30 were notused, the block 25 would distort and tear as it was being pushed into sleeve 32 as the frictional forces would betoo great.

Thus. the block 25 is held compressed by sleeve32 as shown on the left of FIG. 7 whereit has been delivbe replaced by a Inthe event that it becomesladvisable to compress the block in the direction of at least two of its axes and restrain it in the direction of the third axis". it is best to' use a machine 20A such as is illustrated diagrammatically in FIGS. 8 and 9.

Machine 20A is the same as machine 20 with the addition of a compression ram 34A which cooperates with ram 34 as will be described below. After the block 25 has been restrained and/or compressed in the direction of arrow 23 and compressed in the direction of arrow 21, a sleeve 32 is placed over the block 25 as shown in FIG. 8.'Now the ram 34 moves forward in the direction of arrow 27 toward compression ram 34A.

50 and a drive motor 52. A motor 47 moves plates 44 and 46 toward and away from each other to apply restraint and/or compression to a block in the direction of a first axis. Similarly, upper and lower compression bars are moved toward each other to compress the block by thedirection of a second axis after the first axis force is applied. The force applied by plates 44 and 46 may now be removed and the block may be ejected into a sleeve while maintaining the compressive force by means of bars 56 and 57. A pair of ram plates 58 is utilized to eject the block into the restraining sleeve.

Each ram-plate 58, onlyone of which is shown in FIG. 10 is engaged with pusher bar 59 and between a bar 56 and a bar 57. As the opposed bars 56 and 57 move towardeach other in a direction across machine 40, the plates 58 are moved toward each other. As pusher bar 59 is moved along drive members 61 toward the front of machine 40, ram plates 58 push against the compressed block to eject it from the machine. Only one of the drive members 61 is shown in FIG. 10. There is a second one located between the bars 56 and 57 a the left of the figure. Thus it can be seen that the ram plates 58 are properly positioned laterallyby means of the .bars 56 and 57. Once they are positioned behind the block or bun of foam plastic, they serve to eject the block from the machine as pusher bar'59 moves forward along drive members 61.

Machine is shown in perspective in FIG. 11. It is similar to machine 40 and includes a compression ram to obtain compression of the order of about 2-l0 percent inthe direction of the third axis. The figure shows the machine with the bun compressed in the direction of two axes just prior to application of the restraining sleeve and further application of the third axis compression. l

' Machine 70 is seen to comprise a'frame 72, an upper compression plate 46 and, a lower compression plate 44. A plastic block is shown compressed between the pairs of bars 56 and 57 (only one bar 57 is shown). Pusher bar 59 has pushed the ram plates (not shown) against the rear of the foam-block 80.-Liners 82 are in position at the side of block 80. Next the restraining bars 56 or 57 which rest smoothly against the block and are used when a restraining sleeve is employed to hold the compressed block. FIG. 13 is a view similar to that of FIG. 12 of a pair of compression bars 56' or 57' which may be used in machines 40 or 70 whenit is advisable to use restraining straps instead of a restraining sleeve. The bars 56' or 57 areprovided with a plurality of grooves 63 to facilitate the application of the straps tothe block while the block is within the confines of the machine prior to ejection.

FIG. 14 is a diagrammatic view similar to FIG. 9 wherein the block is being ejected in steps to permit the application of straps 65. It is also possible to use the stepped ejection technique to apply straps to blockswhich have been compressed by the machines 20, 40 and 70. When the stepping method is used, either smooth compression bars such as are illustrated in FIG. 12 or grooved compression bars such as are illustrated in FIG. 13 may be used.

It is noted that the open end of the restraining sleeve is in a plane transverse to that formed by the first axis and the second axis. Similarly, each of the straps lies in such a transverse plane.

Since the control system, electric motors and the hydraulic system do not form a part of the invention, details of these elements are not shown.

By way of illustration and not by way of limitation of the scope of the invention, following are examples of results attained with polyurethane foam blocks by utilizing the teachings of the invention:

Uncompressed block Compressed-to desired sizes and shapes. The amount that the block expands, upon removal of the restraints, varies with the.

creep and cure of the plastic under compression. Commercial polyurethane foam expands to about 98 percent of its original dimensions when compressed up to 50 percent of its original dimensions.

While various embodiments of the invention have been shown and described, it is apparent to those skilled in the art that modifications are possible without departing from the spirit of the invention or the scope of the subjoinedclaims.

.The embodiment of the invention'in which an-exclusive property or privilege, is claimed are defined as follows: I

' l. The method of com-pressing a block of foam material to efiectively reduce its volume for /or storage which comprises:

compressing the block in the direction of one of its axes (first axis) an amount of the order between i 1 percent and 70 percent;

compressing the block in the direction of another of its axes (second axis) an amount of the order between l0 percent and 75 percent while maintaining shipment andthe compressive force in the direction of the first axis;

removing the compressive force in the direction of the first axis;

applying restaining means around the block so as to confine the block in the directions of both compressed axes;

removing the compressive force in the direction of the second axis; and

placing a liner along each face of the blocknormal to the second axisbeforecompressing the'block: in the direction of the second axis.

2. The invention of claim 1 wherein the step of applying the restraining means comprises:

ejecting the compressed block into a sleeve whose.

open end is transverse to the plane formed by the step of applyits third axis an amount of the order of 2% to- 10%.

5. The invention of claim 4 wherein: the step of compressing the block in the direction of its third axis is carried out while'applying the restraining means. i i 6. The invention'of claim 1 wherein: v

the step .of' applying the restraining means comprises ejecting the compressed block into a sleeve whose open'end is transverse to the plane of the first axis and the second axis; and 1 theblock is compressed in the direction of its third axis an amountof the order of 2% to 10% concurrent with the applying of the 'restrainin'g'means;

placing a plurality of straps around the compressed block, each of the straps being in a plane transverse to that formed by the first axis and'the second axis; and v r r the .block is compressed in the direction of its'third axis an amount of disorder of 2% to 10% concurrent with the applying of the restraining means.

8. Apparatus for compressing a block of foam. material to effectively reduce its volume and to apply re straining means tohold it in said-compressed state for shipment and/or storage which comprises:

first compressing meansfor compressing the block in i the direction of-a first axis thereof; second compressing means for compressing the block in the directionof a second axis thereof; 'asleeve; aram for. ejecting the compressed block into the sleeve such that the second compressing means and the sleeve serve to prevent the-block fr'omfxpand ing while the block is being fully ejected into .the sleeve; and

.a plate opposed to the ram such that the block i's being. ejected into the sleeve. 9. The invention of claim 8 including:

compressed in the direction of its third axis while third compressing means for compressing the block in the direction of its third axis. 10. The invention of claim 9 wherein: the firstcompressing means comprises a pair of opposed horizontal plates movable toward and away i from each other; and I the second compressing means comprises a pair of opposed upper bars and 'apair of opposed lowerbars, each upper bar being coupled to. a lower bar,

. the coupled bars being movable. toward and away from each other in a direction transverse to the movement of the pair of oppose i horizontal plates.

1 1. The invention of claim 10 wherein:

the pairs of opposed bars carry a plurality of spaced grooves to permit the application of straps to the block in planes transverse to tha t formed by the first axis and the second axis.

12. The invention of claim 8 wherein:

the first compressing means comprises a pair of opmovement of the pair. of opposed horizontal plates.

UNITED STATES PATENT {OFFICE I CERTIFICATE OF CORRECTION vnwm: N 3.811.242 dlwmlzl. ..ls.l4 ww-W Invent0r(s) William H. Hayford, Jr. et a1 It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Address of "William H. Hayford, Jr. Summit Point, Ringwood, NJ. 07456; should read -William H. Hayford, Jr. 44 Summit Point, Ringwood, N.J. 07456;--

Column 1, lineZO, "posible" should read --possible- Column 1, line 40, "lock" should read --block- Column 2, line 29, "FIG. 11." should read -FIG. ll;--

Column 2, line 60, "developes" should read 'develops-- Claim 1, line 14, "restaining" should .read ----:cesc.raining---- Signed and sealed 29th day of October 1974.

(SEAL) Attest:

McCOY M. GIBSON JR. C. MARSHALL DANN Attesting Officer Commissioner of Patents FORM P0405) (0459) .USCOMM-DC suave-Pee i ".5. GDVERNMENT PRINTING OFFICE I I9, 0-365-384, 

1. The method of compressing a block of foam material to effectively reduce its volume for shipment and/or storage which comprises: compressing the block in the direction of one of its axes (first axis) an amount of the order between 1 percent and 70 percent; compressing the block in the direction of another of its axes (second axis) an amount of the order between 10 percent and 75 percent while maintaining the compressive force in the direction of the first axis; removing the compressive force in the direction of the first axis; applying restaining means around the block so as to confine the block in the directions of both compressed axes; removing the compressive force in the direction of the second axis; and placing a liner along each face of the block normal to the second axis before compressing the block in the direction of the second axis.
 2. The invention of claim 1 wherein the step of applying the restraining means comprises: ejecting the compressed block into a sleeve whose open end is transverse to the plane formed by the first axis and the second axis.
 3. The invention of claim 1 wherein the step of applying the restraining means comprises: placing a plurality of straps around the compressed block; each of the straps being in a plane transverse to that formed by the first axis and the second axis.
 4. The invention of claim 1 including: the step of compressing the block in the direction of its third axis an amount of the order of 2% to 10%.
 5. The invention of claim 4 wherein: the step of compressing the block in the direction of its third axis is carried out while applying the restraining means.
 6. The invention of claim 1 wherein: the step of applying the restraining means comprises ejecting the compressed block into a sleeve whose open end is transverse to the plane of the first axis and the second axis; and the block is compressed in the direction of its third axis an amount of the order of 2% to 10% concurrent with the applying of the restraining means.
 7. The invention of claim 1 wherein: the step of applying the restraining means comprises placing a plurality of straps around the compressed block, each of the straps being in a plane transverse to that formed by the first axis and the second axis; and the block is compressed in the direction of its third axis an amount of the order of 2% to 10% concurrent with the applying of the restraining means.
 8. Apparatus for compressing a block of foam material to effectively reduce its volume and to apply restraining means to hold it in said compressed state for shipment and/or storage which compriSes: first compressing means for compressing the block in the direction of a first axis thereof; second compressing means for compressing the block in the direction of a second axis thereof; a sleeve; a ram for ejecting the compressed block into the sleeve such that the second compressing means and the sleeve serve to prevent the block from expanding while the block is being fully ejected into the sleeve; and a plate opposed to the ram such that the block is compressed in the direction of its third axis while being ejected into the sleeve.
 9. The invention of claim 8 including: third compressing means for compressing the block in the direction of its third axis.
 10. The invention of claim 9 wherein: the first compressing means comprises a pair of opposed horizontal plates movable toward and away from each other; and the second compressing means comprises a pair of opposed upper bars and a pair of opposed lower bars, each upper bar being coupled to a lower bar, the coupled bars being movable toward and away from each other in a direction transverse to the movement of the pair of opposed horizontal plates.
 11. The invention of claim 10 wherein: the pairs of opposed bars carry a plurality of spaced grooves to permit the application of straps to the block in planes transverse to that formed by the first axis and the second axis.
 12. The invention of claim 8 wherein: the first compressing means comprises a pair of opposed horizontal plates movable toward and away from each other; and the second compressing means comprises a pair of opposed upper bars and a pair of opposed lower bars, each upper bar being coupled to a lower bar, the coupled bars being movable toward and away from each other in a direction transverse to the movement of the pair of opposed horizontal plates. 